55 research outputs found
Graduate Student Recital:Kristof Kovacs, Piano
Kemp Recital Hall Friday Evening September 20, 2002 7:00p.m
Identification of influence of digital twin technologies on production systems: a return on investment-based approach
The object of this study is the impact of different digital twin solutions on the performance of job-shop manufacturing systems, while economic aspects are also taken into consideration. This paper proposes an approach to analyze the impact of different identification systems on the efficiency and ROI of digital twin deployment in production systems. In order to achieve this aim, let’s analyze the investment and operation cost of different Internet of Things technologies. The next phase of the research work was the definition of performance parameters, which makes it possible to analyze the impact of different digital twin solutions on the productivity of the job-shop manufacturing system. It is possible to choose four financial indicators to analyze the economic impact of digital twin solution on job-shop manufacturing: return on investment, compound annual growth rate, internal rate of return and net present value. Our approach is based on a novel agent-based simulation model using AnyLogic simulation tool. From the results of this productivity analyses, the model computes the financial indicators, which describe the expected financial impact of the investment and operation cost. It is compared the impact of barcodes and radiofrequency identification technologies on the financial and technological impact of the job-shop manufacturing environment. The numerical analysis of a job-shop manufacturing system shows, that the radiofrequency identification-based digital twin solution has 9.2 % higher return on investment, 53 % higher net present value and 1.6 % higher compound annual growth rate. The model can be easily converted to analyze other types of manufacturing systems, which can lead to increased efficiency of digital twin solution
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Modelling hydrological impacts of agricultural expansion in two macro-catchments in Southern Amazonia, Brazil
This study presents the setup, calibration, validation and scenario application of the soil and water assessment tool for two contrasting macro-catchments along the Amazon agricultural frontier in the federal states of Pará and Mato Grosso, Brazil. Calibration and validation of the model are realised for the periods of the most intensive deforestation and agricultural expansion. In order to give consideration to the rapid, however gradual nature of land use change, the model implements an annual land use update combined with a land use dependent soil parameterization of the upper most soil layer. The comparison of these results with the results of a setup with a steady land use distribution shows distinct improvements of the prediction quality. Discharge prediction improves through the application of gradual land use change in the model by 12 % for a 1.8 % deforestation rate per year and 1.2 % for a deforestation rate of 0.7 % per year. Consequently, the validated models are applied to four land use scenarios for the period 2026–2035. Scenario simulation results show effects on the water balance proportional to land use change. Further, the changes in the water balance follow clear seasonal patterns with highest hydrological effects due to land use change during the rainy season in both catchments. Overall, with continuous deforestation, peak discharge increases. Further, the conversion of native vegetation to pasture has the highest impact on the water balance. For example, monthly discharge in the rainy season increases by up to 24 % for a 13 % conversion of Cerrado savannah into pasture
Factors of influence upon overall survival in the treatment of intracranial MPNSTs. Review of the literature and report of a case
BACKGROUND: Intracranial malignant peripheral nerve sheath tumors are rare entities that carry a poor prognosis. To date, there are no established therapeutic strategies for these tumors. METHODS: We review the present treatment modalities and present the current therapeutic dilemmas. We perform a statistical analysis to evaluate the prognostic factors for Overall Survival of these patients. Additionally, we present our experience with a 64-year-old man with a MPNST of the left cerebellopontine angle. RESULTS: To our best knowledge, forty three patients with intracranial MPNSTs, including our case, have been published in the international literature. Our analysis showed gross total resection, radiotherapy and female gender to be beneficial prognostic factors of survival in the univariate analysis. Gross total resection was recognized as the only independent predictor of prolonged Overall Survival. In our case, we performed a gross total resection followed for the first time by stereotactically guided radiotherapy. CONCLUSION: Considering the results of the statistical analysis and the known advantages of the stereotaxy, we suggest aggressive surgery followed by stereotactically guided radiotherapy as therapy of choice
Psychometric Network Analysis of the Hungarian WAIS
The positive manifold—the finding that cognitive ability measures demonstrate positive correlations with one another—has led to models of intelligence that include a general cognitive ability or general intelligence (g). This view has been reinforced using factor analysis and reflective, higher-order latent variable models. However, a new theory of intelligence, Process Overlap Theory (POT), posits that g is not a psychological attribute but an index of cognitive abilities that results from an interconnected network of cognitive processes. These competing theories of intelligence are compared using two different statistical modeling techniques: (a) latent variable modeling and (b) psychometric network analysis. Network models display partial correlations between pairs of observed variables that demonstrate direct relationships among observations. Secondary data analysis was conducted using the Hungarian Wechsler Adult Intelligence Scale Fourth Edition (H-WAIS-IV). The underlying structure of the H-WAIS-IV was first assessed using confirmatory factor analysis assuming a reflective, higher-order model and then reanalyzed using psychometric network analysis. The compatibility (or lack thereof) of these theoretical accounts of intelligence with the data are discussed
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Characterizing rainfall-runoff signatures from microcatchments with contrasting land cover characteristics in southern Amazonia
On the basis of interactions between landscape characteristics and precipitation inputs, watersheds respond differently to different climatic inputs. The objective of this study was to quantitatively characterize controls on runoff generation from two first order micro-catchments in the Amazonia region. The study investigated the variation of hydrological signatures at micro-catchment scale and related these to landscape and land cover differences and weather descriptors that control the observed responses. One catchment is a pasture cleared of all natural vegetation in the early 1980s, and the second catchment is a primary tropical forest with minor signs of disturbance. Water levels and meteorological variables were continuously monitored during the study period (December 2012–May 2013). Water level measurements were converted to discharge, evapotranspiration was quantified using Penman–Monteith equation and catchment pedohydrological properties were also determined. During the study period, mean total rainfall was 1200 mm, and direct runoff ratios were 0.29 and 0.12 for the pasture and forest catchments, respectively. Baseflow index was relatively high in the forest catchment (0.76) compared with pasture catchment (0.63). Results from this study showed that the pasture catchment had a 35% higher mean stream flow. Analysis of selected individual rainstorm events also showed peak discharges, which were attained much faster in the pasture catchment compared with the forest catchment. At both sites, rainfall-runoff responses were highly dependent on surface and subsurface flow generation. Overland flow was observed in the pasture site during intense rainfall events. The pasture catchment exhibited higher event water contribution than the forest catchment. Findings from this research suggest that shallow lateral pathways play a significant role in controlling runoff generation processes in the forest catchment, whereas infiltration excess runoff generation processes dominate in the pasture catchment. The findings in this study suggest that the conversion of forest to pasture may lead to important changes in runoff generation processes and water storage in these head water catchments
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Effects of conversion of native cerrado vegetation to pasture on soil hydro-physical properties, evapotranspiration and streamflow on the Amazonian agricultural frontier
Understanding the impacts of land-use change on landscape-hydrological dynamics is one of the main challenges in the Northern Brazilian Cerrado biome, where the Amazon agricultural frontier is located. Motivated by the gap in literature assessing these impacts, we characterized the soil hydro-physical properties and quantified surface water fluxes from catchments under contrasting land-use in this region. We used data from field measurements in two headwater micro-catchments with similar physical characteristics and different land use, i.e. cerrado sensu stricto vegetation and pasture for extensive cattle ranching. We determined hydraulic and physical properties of the soils, applied ground-based remote sensing techniques to estimate evapotranspiration, and monitored streamflow from October 2012 to September 2014. Our results show significant differences in soil hydro-physical properties between the catchments, with greater bulk density and smaller total porosity in the pasture catchment. We found that evapotranspiration is smaller in the pasture (639 ± 31% mm yr-1) than in the cerrado catchment (1,004 ± 24% mm yr-1), and that streamflow from the pasture catchment is greater with runoff coefficients of 0.40 for the pasture and 0.27 for the cerrado catchment. Overall, our results confirm that conversion of cerrado vegetation to pasture causes soil hydro-physical properties deterioration, reduction in evapotranspiration reduction, and increased streamflow
Advances in the treatment of prolactinomas
Prolactinomas account for approximately 40% of all pituitary adenomas and are an important cause of hypogonadism and infertility. The ultimate goal of therapy for prolactinomas is restoration or achievement of eugonadism through the normalization of hyperprolactinemia and control of tumor mass. Medical therapy with dopamine agonists is highly effective in the majority of cases and represents the mainstay of therapy. Recent data indicating successful withdrawal of these agents in a subset of patients challenge the previously held concept that medical therapy is a lifelong requirement. Complicated situations, such as those encountered in resistance to dopamine agonists, pregnancy, and giant or malignant prolactinomas, may require multimodal therapy involving surgery, radiotherapy, or both. Progress in elucidating the mechanisms underlying the pathogenesis of prolactinomas may enable future development of novel molecular therapies for treatment-resistant cases. This review provides a critical analysis of the efficacy and safety of the various modes of therapy available for the treatment of patients with prolactinomas with an emphasis on challenging situations, a discussion of the data regarding withdrawal of medical therapy, and a foreshadowing of novel approaches to therapy that may become available in the future
Graduate Recital:Kristof Kovacs, Piano
Kemp Recital Hall Wednesday Evening April 14, 2004 7:30p.m
Which tests should be administered first, ability or non-ability? The effect of test order on careless responding
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